Search for dissertations about: "Usnea"
Found 4 swedish dissertations containing the word Usnea.
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1. Lichens in Mountain Rainforests of Tanzania : Studies of Usnea and Calicioids
Abstract : Lichens occur in various habitats. They often have narrow niches and are sensitive to environmental changes leading to their use as bioindicators of environmental disturbances and conditions; air and heavy metal pollution, agricultural toxins, assessing forest continuity and drought tolerance. READ MORE
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2. Phylogenetic Studies in Usnea (Parmeliaceae) and Allied Genera
Abstract : This thesis deals with the phylogeny of the lichen genus Usnea (Parmeliaceae, Ascomycetes). The relationships and the morphological variation among Usnea species has been studied, as well as the relationship of Usnea to allied genera. Two species, U. florida and U. READ MORE
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3. Ecology of lichens in boreal coniferous forests with reference to spatial and temporal patterns
Abstract : The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. READ MORE
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4. Forest edges in boreal landscapes - factors affecting edge influence
Abstract : The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. READ MORE